The U.S. Coast Guard heavy icebreaker Polar Star (WAGB 10) was built by Lockheed Shipbuilding and Construction Co. of Seattle, Wash., and commissioned in 1976. It is one of the largest ships in the Coast Guard and one of the world’s most powerful non-nuclear ships. It is home-ported in Seattle.
Polar Star’s three shafts are turned by either a diesel-electric or gas turbine power plant. Each shaft is connected to a four-blade, controllable-pitch propeller that is 16 feet in diameter. The diesel-electric plant can produce 18,000 shaft horsepower (13,425 kilowatts) and the gas turbine plant 75,000 shaft horsepower (55,925 kilowatts).
Polar Star displaces 13,200 metric tons and can break through ice up to 6 feet thick at a speed of 3 knots. While backing and ramming, it can break ice up to 21 feet thick.
Source: U.S. Coast Guard
